1. Field of the Invention
The present invention relates generally to semiconductor integrated circuits and, in particular, to a sense amplifier device used in integrated circuit memories.
2. State of the Art
With the advent of electronic devices such as laptop and hand-held computers as well as other electronic devices that utilize memory components, the need has increased for circuitry that operates efficiently at lower power supply voltages. Additionally, in order to increase performance speeds in memory components, the physical dimensions of the operational circuits have also been decreased which, in turn, requires lower voltages. Older memories and the sense amplifiers used to read stored information from those memories were developed for use with 5.0 volt and 3.0 volt supply voltages and have generally proven inadequate for use with lower voltage memory devices.
In conventional sense amplifier designs, such as in the case of a DRAM sense amplifier, a so-called “precharging” of the sense amplifier occurs prior to a read operation of the stored memory information. As the voltage levels to such memory devices are reduced, the precharge potential, which is generally one-half the power supply potential, is also reduced. In the case of an MOS memory configuration, when the absolute value of the threshold voltage of a MOS transistor of a sense amplifier is increased, generally due to a “body affect,” and the precharge potential is reduced due to a lowered operating voltage, the difference between the precharge potential and the threshold voltage becomes smaller. Such a small potential difference results in a reduction in the sensing speed and may even result in the failure of a conventional sense amplifier to transition into a sensed state when presented with the data potential in the memory element. Therefore, a need exists for providing an improved circuit for improving the sense operation speed of a sense amplifier in a reduced or low voltage memory device configuration.